Tuesday, December 10, 2013

Deep Desulfurization of Fuels by Extraction with 4-Dimethylaminopyridinium-Based Ionic Liquids

Energy Fuels, 2013, 27 (8), pp 4617–4623, DOI: 10.1021/ef401015c
Deep Desulfurization of Fuels by Extraction with 4-Dimethylaminopyridinium-Based Ionic Liquids
Abstract
Qianli Wang , Lecheng Lei , Jingke Zhu , Bin Yang , and Zhongjian Li *
zdlizj@zju.edu.cn
Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Department of Chemical and Biological Engineering, Zhejiang University, Yuquan Campus, Hangzhou 310027, China
Abstract
Researchers show that synthesized three 4-dimethylaminopyridinium-based ionic liquids (ILs), N-ethyl-4-dimethylaminopyridinium dicyanamide ([C24DMAPy][N(CN)2]), N-butyl-4-dimethylaminopyridinium dicyanamide ([C44DMAPy][N(CN)2]) and N-hexyl-4-dimethylaminopyridinium dicyanamide ([C64DMAPy][N(CN)2])are efficient for aromatic sulfur compounds extraction from fuels.
Study results suggested that 4-dimethylaminopyridinium-based ILs hardly dissolved in the fuels, while the solubility of 97# gasoline in ILs varies from 7.0 wt % for [C24DMAPy][N(CN)2] to 12.4 wt % for [C64DMAPy][N(CN)2] and the solubility of 0# diesel in ILs varies from 6.7 wt % for [C24DMAPy][N(CN)2] to 9.7 wt % for [C64DMAPy][N(CN)2].
The sulfur partition coefficient was examined, as well. In the case of model gasoline, the thiophene (TS) partition coefficient in model gasoline varies from 0.885 for [C24DMAPy][N(CN)2] to 1.218 for [C64DMAPy][N(CN)2]. In the case of model diesel, 4-dimethylaminopyridinium-based ILs exhibit a relatively higher sulfur partition coefficient, compared to alkyl modified pyridinium-based ILs. 1H NMR results confirmed that the high aromatic π-electron density of the dimethylaminopyridinium cation was the main cause of the good extraction performance. 1H NMR results also confirmed the KN sequence for each IL ([C24DMAPy][N(CN)2] < [C44DMAPy][N(CN)2] < [C64DMAPy][N(CN)2]) is mainly due to the sulfur compounds and ILs structures. Furthermore, the extractive selectivity results indicated a more preferable extraction of TS than toluene with 4-dimethylaminopyridinium-based ILs.
Full Text Source (Subscription or Fee): http://pubs.acs.org/doi/abs/10.1021/ef401015c

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